CONGENITAL HEART DISEASE Flashcards
What are the common forms of acyanotic congenital heart disease?
Ventricular septal defect
Patent ductus arteriosus
Pulmonary stenosis (remember that critical PS will cause cyanotic disease)
Atrial septal defect
Coarctation of the aorta
Aortic stenosis
What the common forms of cyanotic congenital heart disease?
Tetralogy of Fallot
Transposition of the great arteries
Critical pulmonary stenosis
Pulmonary atresia
What are the different types of atrial septal defect and what are the differences?
Ostium primum
Ostium secundum
The less common type ostium primum develops as a result of incomplete fusion of the septum primum to the ventricular septum during heart development. It is therefore located lower in the atria. The atrial septal defect is said to exist when the two atrial septums try to fuse at birth but fail to due to this opening. It usually presents as symptomatic.
The more common ostium secundum is naturally created as part of the system that allows a right to left atrial shunt with the foramen ovale in the womb. The atrial septal defect is said to exist when the two atrial septums of the heart fail to fuse properly at birth. It is usually asymptomatic.
https://www.youtube.com/watch?v=ed6__8FaSOU
What is the difference between atrial septal defect and patent foramen ovale?
Both the ostium primum and ostium secundum atrial defects occur in the septum primum (associated with the left side of the heart in development). If they stay open at birth, fusion of the two atrial septums creates a large hole that remains open.
The foramen ovale is a hole in the septum secundum (associated with the right side of the heart in development). This only opens in conditions of raised left atrial pressure or volume.
What are the possible clinical features of atrial septal defects?
Widely split and fixed second heart sound (S2)
Pulmonary flow murmur - increased blood volume means that there is often be a soft, ejection systolic murmur in pulmonary area. Not to do with a structural defect of the valve.
A small proportion have a tricuspid flow murmur - rumbling mid diastolic murmur at the left sternal edge
Abnormal right ventricular electrical impulse
Paradoxical venous emboli if valsalva manoeuvre is performed
What are the differences in ECG changes between ostium primum and ostium secundum atrial septal defects?
Ostium secundum (70% of ASDs): RBBB with RAD
Ostium primum: RBBB with LAD
What is the most common type of congenital heart defect to be found in adulthood?
Atrial septal defect - usually ostium secundum
What is the syndrome associated with ostium secundum atrial septal defects?
Holt-Oram syndrome - autosomal dominant disorder that affects bones in the arms and hands
Fetal alcohol syndrome
What is the syndrome associated with ostium primum?
Down syndrome
What is the treatment and the purpose of the treatment of atrial septal defects?
Surgical (transcatheter)
ASD can cause heart failure in later life. Best to treat at 3-5 years old
What is the most common type of congenital heart defect?
Ventricular septal defect
What are the risk factors for developing ventricular septal defects?
Down syndrome
Fetal alcohol syndrome
Gestational diabetes
Maternal SLE
Rubella infection
Drugs:
Lithium
How do we classify ventricular septal defects?
By size:
Small
Medium
Large
By location:
Type 1 - infundibular (related to the aortic valve)
Type 2 - perimembranous (accounts for 70% of VSDs)
Type 3 - Inlet (atrioventricular septal defect)
Type 4 - muscular (accounts for 20% of VSDs)
Type 5 - Gerbode (absence of atrioventricular septum)
How long after birth does a ventricular septal defect usually manifest?
A few weeks
What are the clinical features of small ventricular septal defects and what is the other name given to such defects?
Also called maladie of Roger
Child is normally asymptomatic and a pansystolic murmur with a possible palpable thrill is heard at the left lower sternal border.
What are the clinical features of medium ventricular septal defects?
Symptoms:
Slow weight gain
Difficulty feeding - due to tachypnoea
Recurrent chest infections secondary to pulmonary congestion
Signs:
Increased cardiac electrical impulse
Palpable thrill
Harsh pansystolic murmur, loudest in third and fourth left intercostal spaces
Heart failure will eventually develop.
What are the signs of heart failure in an infant?
Tachycardia
Tachypnoea
Hepatomegaly
Pallor and sweating
What is the major paradoxical clinical difference between a medium and a large ventricular septal defect?
The murmur in large VSDs might actually be quieter than medium VSDs
How do you treat heart failure in children?
Diuretics
ACE inhibitors
What is patent ductus arteriosus?
The ductus arteriosus connects the aorta to the left pulmonary artery and usually closes by the fourth day of life. PDA is diagnosed if it does not close 3 weeks to one month after birth.
What are the risk factors for patent ductus arteriosus?
Preterm infants
Down syndrome
High altitudes
What are the clinical features of patent ductus arteriosus?
Bounding pulse - wide pulse pressure
Murmur - initially systolic develops into a continuous machinery murmur
Failure to thrive
How do you treat a patient with a patent ductus arteriosus?
With surgery at the age of 1 unless it needs closing earlier.
Prostaglandin E2 inhibitors - NSAIDs - indomethacin
What are the two types of coarctation of the aorta?
Preductal coarctation
Postductal coarctation
Which type of coarctation of the aorta is more symptomatic?
Preductal
Why is preductal coarctation of the aorta more symptomatic than postductal coarctation of the aorta?
In preductal coarctation of the aorta, the lower pressure created by the narrowing is at a point where blood can therefore flow from the pulmonary artery to the aorta through a patent ductus arteriosus and therefore create a right to left shunt.
In postductal coarctation, the collecting blood before the narrowing means that the pressure builds and therefore blood flows through a patent ductus arteriosus from the aorta into the pulmonary artery, creating a left to right shunt. This is still a problem but not as symptomatic initially.
What are the syndromes or conditions commonly associated with preductal coarctation of the aorta?
Turner syndrome
Neurofibromatosis
Is coarctation of the aorta more common in boys or girls?
Boys (2:1), despite the association with Turner syndrome
What are the clinical features of preductal coarctation of the aorta in the neonate?
Cyanosis in the lower limbs from birth
Absent femoral pulses
Heart failure once the PDA closes
What are the symptoms of coarctation of the aorta in children?
Difficulty breathing
Trouble feeding
Failure to thrive
Dizziness
Syncope
Chest pain
Fatigue
Headaches
Nosebleeds
What are the signs of coarctation of the aorta?
Wide difference in blood pressure between upper and lower limbs
Radial - femoral delay pulse
Weak femoral pulses
Radial - radial delay (pre-left subclavian artery)
What may be seen on x-ray of someone with coarctation of the aorta?
Increased cardiac shadow from heart failure
‘Figure 3’ sign - if there is poststenotic filling
Rib notching on the left (particularly ribs 3 and 4)
Why does rib notching occur with coarctation of the aorta?
This is because of the anastomosis between the intercostal arteries. Because the arteries on the right have such high pressure as they come off the right subclavian artery (before the coarcted segment), they can actually send blood in the reverse direction along the left intercostal arteries (which have a low pressure). This makes these left arteries pulsate and rub against the ribs therefore degrading them. This causes the notching.
What imaging technique might you use to confirm coarctation of the aorta?
Magnetic resonance angiography
CT angiogram
How can we treat preductal coarctation of the aorta in a neonate?
Prostaglandin infusion to keep PDA open
Transfer to cardiac centre for specialist surgery
How can we treat postductal coarctation of the aorta in a child (or adult)?
Surgical correction using either:
Balloon dilatation
Resection of the coarcted segment with end to end anastomosis
What are the complications of coarctation of the aorta?
Hypertension and all associated complications
Berry aneurysm
Claudication in legs
What are the four cardinal anatomical features of tetralogy of Fallot?
Right ventricular outflow tract obstruction (RVOT) which may be any of infundibular stenosis, pulmonary stenosis or a combination
This causes - Right ventricular hypertrophy
Large ventricular septal defect
Aorta overriding the ventricular septum
It is therefore usually a right to left shunt, hence the cyanosis.
What are the clinical features of tetralogy of Fallot?
Cyanosis
Clubbing
Tet spells - cyanotic spells
Failure to thrive
Feeding difficulties
Loud and single S2
Loud ejection systolic murmur maximal at the third left intercostal space
What would the ECG of a child with tetralogy of Fallot show?
Right axis deviation
Right ventricular hypertrophy
What is the classic sign on chest x-ray associated with tetralogy of Fallot?
Boot sign due to right sided hypertrophy
What are the conditions associated with tetralogy of Fallot?
Chromosome 22 deletions
DiGeorge syndrome
What do toddlers often do to relieve symptoms of cyanosis? How does this work?
Squat down
This kinks femoral arteries in the legs
This leads to increased vascular resistance and therefore increased blood pressure
This increases pressure in left side of heart so that it is now higher than right side and shunt is reversed.
How would you manage someone experiencing a hypercyanotic episode as a result of tetralogy of Fallot (tet spell)?
Keep child calm
Encourage squatting position
Give O2 and fluids
Morphine
Sodium bicarbonate to correct acidosis
Propranolol to cause peripheral vasoconstriction and relieve infundibular spasm.
How do you more definitely treat tetralogy of Fallot?
Surgery in the first year of life
Is transposition of the great arteries more common in males or females?
Males (3:1)
What must be present for someone with dexo-transposition of the great arteries to be living at all?
A defect allowing mixing of the two circulations. eg ASD, VSD or PDA
What is the biggest risk factor for developing transposition of the great arteries?
Maternal diabetes
What are the clinical features of dextro-transposition of the great arteries?
Cyanosis very early in life - first day or two
What medication is needed to help keep a newborn alive if born with dextro-transposition of the great arteries?
Prostaglandin E1 to make sure ductus arteriosus reopens or stays patent.
How do we definitively treat dextro-transposition of the great arteries?
Surgical switch of the arteries
What is levo-transposition of the great arteries?
This is an acyanotic congenital heart defect where the heart is the wrong way round. The complications of this arise from the fact that the right ventricle is now being asked to pump against the pressure of the systemic system, something it was not designed to do.
What is Eisenmenger’s syndrome?
This is the reversal of a left-to-right shunt in a congenital heart defect due to pulmonary hypertension.
What types of congenital heart defects might lead to Eisenmenger’s syndrome?
Atrial septal defect
Ventricular septal defect
Patent ductus arteriosus
What are the features of Eisenmenger’s syndrome?
Original murmur disappears
Cyanosis
Clubbing
Right ventricular failure
Haemoptysis
Paradoxical embolism
How do you treat Eisenmenger’s syndrome?
Heart transplant
